This invention relates to a seal assembly disposed between and within two stationary members employed on an engine and having a common passageway formed therein to communicate coolant therethrough.
Cooling systems as used upon internal combustion engines have ,several passages for coolant flow. Often some of the passages cannot be efficiently contained completely within the major members that make up the engine, such as the block, cylinder heads, front cover assembly, and manifolds, and must be routed externally. These external passages usually consist of hoses, single piece tube assemblies with O-rings or other seals, press in rubber seals, expandable rubber seals, and other devices which form a static seal between adjacent members of an engine. An additional function of some sealing apparatus that form a passage is introducing a restriction in a coolant passage to control flow. Nearly all engines that use liquid for cooling purposes require a device or selection of passage sizing which restricts the flow of coolant to avoid overcooling or reduce cavitation. Selective sizing of the of the seal""s bore will influence the volume of coolant which may pass through it and the adjoining member.
When engines are originally manufactured, their design is put forth which anticipates the use of one or more of the seal types mentioned above. Few different designs, if any, are interchangeable with each other during assembly, maintenance, or repair of an engine. Thus, particularly in the case of a single piece tubular device with O-ring seals, if leakage occurs. at least one of the major engine members must be removed and replaced upon the engine in order to replace the tube or O-ring seals. Even though the original tubular units can be cut or broken out of their original position, available replacement parts duplicate the original single piece design and require removal and replacement of one or more major engine members.
Although several types of water seals exist for various purposes, none are able to efficiently and directly replace the above mentioned single piece tubular design which seals and is positioned within existing coolant passage bores in the adjacent engine members.
Two prior designs are U.S. Pat. No. 3,603,618 to Stratton (1971) and an improvement on same, U.S. Pat. No. 4,234,198 to Marten, Smith (1980) both disclose a single elastomeric seal with ferrule assembly which seals directly upon the face of the members. Both designs have an inside diameter which is as large or larger than the bore of the passage within the members which they form a passage with. These designs require a means external of the coolant passages fbr mounting and alignment. As mentioned in their description and claims, both of these seal designs utilize notches, annular cut-outs, grooves, or bosses, for alignment and mounting purposes, which require original engine manufacturing that anticipates their use. Since both of these prior designs seal directly against the face of the engine members, it is required that there be a substantial radially flat area machined upon the face of each member of the engine to provide an accommodating surface for the elastomeric seal. Another deficiency in these designs is that the elastomeric seal does not have sufficient volume of resilient material to maintain outwardly pressure and static seal over an extended time period. This weakness is due to heating and cooling cycles common with internal combustion engines, which tend to stiffen and eventually cause slight shrinkage to these types of material. Evidence of this is U.S. Pat. No. 4,234,198, as identified above, which attempts to add resilient material and increase the clamping forces. Mounting and space limitations limit the range, usefulness, and reliability of these prior designs. These prior designs would be prohibited where there are substantial contours, space limitations, or lack of a substantially flat machined surface on the radially extending face surrounding the coolant passages of each adjacent member of the engine.
Another prior design, U.S. Pat. No. 4,400,018 to Abbes, Rouaud, Forges, and de Villepoix (1983) discloses a seal assembly for joining two opposing pipe ends. The inside diameter of the seal assembly is as large or larger than the bore of the pipes that it connects. The two opposing flanges are flat except for a cradle for the extensible member to reside upon. The two opposing flanges must also be welded onto the end of each pipe. O-rings are used between the face of each flange and the extensible members. The assembly requires two separate extensible members with conical shaped faces. A two piece moveable member, with a double conical shape is wedged in between the extensible members and presses against the latter mentioned conical faces. The moveable member also bears against the rear faces of the radial flanges to prevent the pipes from moving apart. No part of this invention resides within the passages of the members or in this case pipes. Mounting relies on the front and back sides of external, flat, welded on flanges. All sealing is accomplished with two separate O-rings which each seal against three surfaces. The internal diameter of the tubular member is substantially the same diameter as the corresponding pipes. This seal assembly requires a multiple of flat radial surfaces for mounting means. The extensible members are of rigid material and do not serve to form the seal between the pipes. Sealing is accomplished by pressure exerted upon the. O-rings by the extensible member to form sealing contact between the flanges and the tubular member. It would be nearly impossible to utilize this seal assembly between rigidly mounted members of an engine which do not have several inches of space between them and which do not have a tubular projection with flanges incorporated upon them during their manufacture.
Another prior art example is U.S. Pat. No. 4,417,735 to Heisler (1983) reveals a sealing device disposed between adjacent members of an engine. This design also has an inside diameter as large or larger than the bore of the passage in the members which it seals. A centering bead exists on one of the members to provide a means of locating the seal assembly. Clamping upon a trapezoidal shape is used to cause expansion outwardly against the members. This is, a rigid design with resilient material being used only in the form of gasketing applied to the outer surfaces. The sealing and mounting of this seal assembly is completely dependant on the protruding surfaces of the members being precisely machined to form a corresponding mechanical fit. This design allows a component such as a manifold to be removed without disturbing other members. However it does not allow for the seal itself to be installed or removed alone. The seal assembly must be placed upon one of the engine components while one of the component is being installed. Again, for reasons similar to those mentioned above, this seal assembly would be nearly impossible to use between rigidly mounted adjacent members of an engine.
None of these prior art examples are capable of mounting within the bore of existing passages, or have any provisions for control of coolant flow. Further, none are capable of sealing where there are no special machined surfaces or other devices provided upon the face of each adjacent member.
An object of this invention is to provide a more serviceable seal assembly of the above type, particularly adapted for applications in the cooling system of internal combustion engines. The seal assembly comprises an annular ferrule, an elastomeric seal circumferentially disposed thereabout and a pair of annular mounting rings. The annular mounting rings provide a radial surface to engage with the elastomeric seal and also extend into and seal within the coolant passage bore of each adjacent member. A clamping means circumferentially surrounds the seal and ferrule to apply a clamping force radially inwardly on the seal to expand the sidewalls thereof into sealing contact with the annular mounting rings. The annular mounting rings may also provide for control of coolant flow by selection of bore sizing.
Accordingly, several objects and advantages of the present invention are;
a) to provide a seal assembly which can easily be installed without removing any major engine members such as a cylinder head or front cover assembly;
b) to provide a seal assembly which can easily be installed by hand without any additional machining, welding or fabrication;
c) to provide a seal assembly which mounts and seals within opposing passages employed on members of an engine and which are separated from each other by a gap which is at least wide enough to install the various parts of the invention;
d) to provide a seal assembly which utilizes existing bores within the members to provide all necessary mounting and alignment of the various parts of the seal assembly;
e) to provide a seal assembly with a low overall profile which is tolerant of substantial contours, space limitations, or lack of a substantial radially flat area, which may be on or near the face of one or both adjacent members of the engine;
f) to provide a seal assembly which can be more easily serviced when necessary to repair leaks or perform other maintenance;
g) to provide a seal assembly which by it""s construction is mostly reusable;
h) to provide a seal assembly which by selective sizing of it""s bore can be used to control the volume of coolant flow;
i) to provide a seal assembly which no longer causes many other engine parts such as gaskets, seals, coolant, oil and filters, and other used but serviceable parts, which may not be at the end of their useful service life, to be replaced prematurely;
j) to provide a seal assembly which is at least as reliable as prior art and has sufficient volume and shape of resilient material to withstand aging which is inherent with the frequent heating and cooling cycles common to internal combustion engines, thus not needing periodic adjusting of the clamping means or other undesirable maintenance.